Lubricant compositions

ABSTRACT

WHEREIN R, R1, R2, R3, R4 and R5 represent certain specified substituent groups. The sulphurisation is carried out at a temperature of up to 180*C in the absence of a solvent or in the presence of a non-polar solvent. Lubricating compositions may contain a major amount of lubricating oil and a minor amount of the said sulphurised compound. preferably, the said sulphurised compound is incorporated into the lubricating composition in an amount of from 0.1 to 10% by weight.   A process for preparing an oil-soluble metal-free phosphorusfree substance for use as a lubricating additive, which comprises sulphurising a compound having the general formula:

United States Patent [1 1 Askew et al.

[ May 6,1975

i 1 LUBRICANT COMPOSITIONS [75] Inventors: Herbert Frank Askew; Gerald John Joseph Jayne; John Scotchford Elliott, all of Bracknell. England [73] Assignee: Edwin Cooper & Company Limited, Bracknel], England 221 Filed: ,Apnll, 1974 211 App]. No.: 459,938

[30] Foreign Application Priority Data Primary Examiner-Delbert E. Gantz Assistant Examiner-I. Vaughn Attorney, Agent, or FirmBa -:on & Thomas [57] ABSTRACT A process for preparing an oil-soluble metal-free phosphorus-free substance for use as a lubricating additive, which comprises sulphurising a compound having the general formula:

R 4 5 n R 5 (B) 5 R1 R R2 wherein R, R R R, R and R represent certain specified substituent groups. The sulphurisation is carried out at a temperature of up to 180C in the absence of a solvent or in the presence of a non-polar solvent. Lubricating compositions may contain a major amount of lubricating oil and a minor amount of the said sulphurised compound. preferably, the said sulphurised compound is incorporated into the lubri eating composition in an amount of from 0.1 to 10% by weight.

13 Claims, No Drawings LUBRICANT COMPOSITIONS This invention relates to sulphurised products having utility as lubricant additives and lubricating composi tions containing them. The invention also relates to a process for preparing sulphurised products, the products so prepared and lubricating compositions containing such products.

Antioxidant additives used in lubricating oils, particularly, but not exclusively, automotive lubricants, require a combination of properties which is difficult to meet in practice. Such additives must, of course, impart a high degree of resistance to oxidation to the lubricant, but in addition must be reasonably inexpensive, must be compatible with various other additives commonly used in lubricants, must have adequate thermal stability and must satisfy various other criteria of suitability, such as the ability to protect copper-lead bearings from corrosion. Very many different types of antioxidants have been proposed, and in some cases have been commercially used on a comparatively small scale. However, for many years the type of antioxidants which have been very widely used as the most suitable general purpose antioxidants for automotive and other lubricants are metal, particularly zinc, salts of dihydrocarbyl dithiophosphoric acids.

However, the need for lubricant developments to keep pace with engine developments has given rise recently to difficulties in the use of metal dithiophosphate salts as antioxidants. The metal content of these additives is a source of ash and there is a growing tendency for the quality standards laid down by manufacturers and other interested organisations to specify low-ash lubricant formulations for modern engines. Attempts have been made to develop dithiophosphate derivatives, which do not contain metal, in order to meet these requirements. However, such developments have been forestalled, at least to some extent, by yet another development in engine design, namely the use of catalytic devices in engine exhausts to minimise pollution caused by vehicle emissions. The catalysts used in such devices are sensitive to phosphorus compounds and can become poisoned and ineffective if exposed to such compounds. Consequently, the need has arisen for antioxidants which do not contain metal or phosphorus, and yet still meet all the requirements for antioxidants formerly satisfied by the metal dithiophosphates.

We have now found certain sulphurised products which are, at least in the preferred embodiments, very effective antioxidants in lubricating compositions such as crankcase lubricants. The sulphurised products are also useful for other purposes, for example as loadcarriers in gear oil formulations.

Accordingly in one aspect of the present invention there is provided a lubricating composition containing a major amount of lubricating oil and a minor amount of a sulphur containing additive wherein said additive is a sulphur containing norbornenyl compound having the general formula:

wherein:

a. each of R, R and R when taken singly is a hydrogen atom, an alkyl group containing from 1 to about 15 carbon atoms, an aryl group containing from 6 to about 15 carbon atoms or a cycloalkyl group containing from 4 to about 10 carbon atoms;

b. each of R and R when taken singly is a hydrogen atom, an alkyl group containing from 1 to about 15 carbon atoms; an aryl group containing from 6 to about 15 carbon atoms; a cycloalkyl group containing from 4 to about 10 carbon atoms or an alkenyl group containing from 2 to about 10 carbon atoms or R and R taken together form the group CHY.CY=CY in which Y is a hydrogen atom or a methyl group or R together with R form an alkylidene group containing from 1 to about 6 carbon atoms; and

c. R is a hydrogen atom or an alkyl group containing from 1 to about 15 carbon atoms; or, wherein said additive is the oil-soluble sulphur containing norbornenyl product resulting from sulphurising a compound having the general formula:

wherein R, R, R R, R and R are as hereinbefore defined at a temperature of up to C, said sulphurisation being carried out in the absence of a solvent or in the presence of a non-polar solvent.

The foregoing compounds of formula (A) are known compounds and are described in U.S. Pat. No. 3,586,700, which also describes the preparation of the compounds by sulphurisation of norbornenyl compounds to form the trithiolan derivatives depicted above. The sulphurisation reaction of U.S. Pat. No. 3,586,700 is carried out necessarily in the presence of certain highly polar organic solvents.

However, in a very important aspect of the present invention there is provided a process for preparing an oil-soluble, metal-free, phosphorus-free substance suitable for use as a lubricant additive, which process comprises sulphurising a compound having the general formula:

3 wherein R. R. R R, R, and R are as hereinbeforc defined. at a temperature of up to lBU C, said sulphurisation being carried out in the absence of a solvent or in the presence of a non-polar sovent, and thereafter removing any oil-insoluble constituents from the resulting sulphurised product.

Examples of compounds which maybe sulphurised in the process of the present invention are norbornene. S-vinylnorborncnc. dicyclopentadienc and methyl cyclopentadiene dimer of which dicyclopcntadienc and methyi cyclopentadienc dimer are especially preferred.

If desired the process of the present invention may he carried out in the presence of a catalyst of the type commonly used in sulphurisation reactions, for example tertiary amines such as triethylarninc or pyridine, secondary amines such as di'isopropylamine, di butylamine. and dicyclohexylaminc and primary amines such as cyclohexylamine and the 'yo-dirnethyl tertiary alkyl primary amines available commercially under such trade names as Primcne JM T and Prirncne Sl-R. Other catalysts which may be used include:

,5 7 Dimercapto 1,3.4: thiadiazolc .5 Dimercapto 1.1,4- thiadiazole ,5 Bist'toctyldithio] L14 thiadiazole Mercaptobenzothiazole sulphide ions, cg. provided by sodium sulphide Aikanolaniines Diphenyl guanidinc A Mixture of NaOH and mercaptobenzothiazolc peroxide such as the material marketed as tertiary butyl hydroperoxide consisting of about 70% of that peroxide together with about 30% di+butyl peroxide Particularly preferred catalysts are comhinations of an amine and a thiadiazole derivative.

The amount of catalyst used is not critical, but normally will be about t).l to 109'? for example, from 2 to more preferably [ll to 10% and most preferably 0.3 to 2%. by weight based on the weight of the compound to be sulphurised.

The process of the present invention may also be carried out in the presence of a small amount, cg. not more than molar percent based on the compound to be sulphurised, of a solubilising agent. Examples of solubilising agents which may be used are:

Conjugated dior poly-olefins such as alloocimcne l,5 dirnethyll.4,h-octatriencl Non-coniugated dior poly olefins such as cyclododecatrienc and lfi-cyclooctadicne Dialkyl maleates, preferably containing from 1 to 12,

more preferably 4 to 8, carbon atoms in each alkyl group, cg. dibutyl maleatc Alkenyl succinic acids or anhyriridcs thereof. preferably containing 8 to II carbon atoms in the alkenyl group. such as dodecenyl succinic acid Allsyl mercaptans, preferably containing 8 to l2 carbon atoms such as t dodecyl mercaptan Polyisobutenyl succinimides Mercaptobenzothiarole Bcnr'othiazole disulphide Alkenoic acids, preferably containing from h to IR carbon atoms such as olcic acid Alkyl esters of alkenoic acids such as octyl methacrylate Ethoxylated amines such as the material available commercially under the trade name Ethomeen Tl 5 (ill 4 Dimcrised alkenoic acids, preferably containing from 18 to 36 carbon atoms Dicyclopentadiene hydrate Alkanols, such as isodecanol.

Such solubilising agents may assist in increasing the proportion of oil-soluble constituents in the product of the sulphurisation reaction and, when used, will normally be present in an amount of l to 25, preferably 2 to l5, molar percent. Within this range it is preferred to use as small an amount of solubilising agent as possible consistent with obtaining a reasonable amount of oil-soluble product (for example not more than 25-30filby weight, preferably less, of the product should be oil-insoluble). The effectiveness of the solubilising agent has been found to be dependent in part on the proportion of sulphur used in the sulphurisation reaction. effectiveness decreasing with increasing proportions of sulphur used. Moreover, as exemplilied hereinafter some solubilising agents are more ef fective than others and solubilising agents such as alloocimcne, dibutyl maleatc, dodecenyl succinic acid, t-dodeeyl mercaptan, Ethomeen Tli, olcic acid and mercaptobenrruhiazole are most preferred.

In the process of the present invention the sulphur is preferably used in an amount of from 0.1 to 4 moles per mole of compound to be sulphurised, with an amount of about 1 to 2 moles per mole of compound to be sulphurised being most preferred. The sulphurisation can be conveniently carried out by merely mixing the reactants, including any catalyst. and/or solubilising agent used, and heating. Alternatively, the compound to be sulphurised can be added to hot sulphur. However, when using a relatively high amount of sulphur, ie. an amount in the upper end of the preferred range, it is preferred to add the sulphur in portions over an initial period to the compound to be sulphurised maintained at the reaction temperature and then to continue maintaining the reaction temperature for a further period.

ln general a reaction temperature of at least C. is preferred, with at least 0 or l()OC. being most preferred for providing the preferred sulphurised materials as hereinbefore described. Also, a reaction temperature no greater than l6tlC is preferred. Sulphurisation is normally completed in from 0.5 to 24 hours depend ing on the reaction temperature. At the optimum temperature of about llll to l4UC. a reaction time of about 2 hours is generally found to be most satisfac' tory, the co-rcactants either being mixed and heated for 1 hours or the sulphur being added to the com pound to be sulphurised in portions over, for example l hour at l2UC and this temperature then being maintained for a further hour,

The sulphurisation may, if desired, be carried out in an inert atmosphere such as a nitrogen blanket. The pressure at which the sulphurisation is carried out is not critical, but is preferably not reduced to a level at which significant amounts of the compound being sulphurised are lost from the reaction system by distillation.

Although it is preferred to carry out the sulphurisation in the absence of a solvent it is also possible to carry out the reaction in the presence of a non-polar solvent, examples of the latter being petroleum ether, toluene, benzene, xylene and mineral oil (especially a mineral lubricating oil).

After completion of the sulphurisation any oilinsoluble constituent of the product may be removed by any convenient method using well known techniques such as solvent extraction or dissolving in oil followed by filtration. However, if the reaction is carried out under careful control at the optimum conditions the whole product is frequently oil-soluble and removal of oil-insoluble constituents is not necessary. Accordingly, reference made herein and in the appended claims to removal of oil-insoluble constituents is to be understood to mean. unless the context denotes otherwise, removal of oil-insoluble constituents if, and as,

necessary.

A preferred technique for removal of oil-insoluble by products is to initially strip off excess olefin which would otherwise solubilize the insoluble component and to then add excess petroleum ether to precipitate an insoluble phase which can be removed. The petro leurn ether is then stripped off to yield a totally oilsoluble product.

in a preferred embodiment of the invention dicyclopentadiene is sulphurised using 2 moles of sulphur per mole of dicyclopentadiene at a temperature of about l20C using di-isopropylamine and 2,5- bis(t-octyldithio)-l,3,4- thiadiazole as catalysts, and, optionally, one of the most preferred solubilisers listed above.

In a further aspect the present invention also includes the oil-soluble, metal-free, phosphorus-free products prepared by the process of the present invention.

It is to be understood that as with all chemical substances purity, in an absolute sense, is impossible to achieve and the sulphurised olefins of the present in vention may contain, as a result of contaminants present in the starting materials, a trace of metal and/or phosphorus. However, such traces should be present in such minute quantities as to be of no practical significance and it is to be understood that the starting materials should not be grossly contaminated with metal and/or phosphorus compounds. However, commercially available grades of starting materials are normally completely adequate in this respect and any contamination arising therefrom is far below any level of practical significance.

The products of the process of the present invention preferably contain from about to 40% by weight of sulphur and reaction conditions and proportions of coreactants may be adjusted in order to vary the sulphur content of the product. Further the products of the process of the present invention are believed to contain substantial amounts of the trithiolan derivatives hereinbefore depicted in formula (A).

Preferably the lubricating compositions of the present invention comprise from 0. l% to l0%, more preferably 0.25% to 5%, by weight of the oil-soluble, metalfree, phosphorus-free products and/or compounds of foregoing formula (A) and the lubricating oil may be any of the well known mineral or synthetic oils of appropriate viscosity characteristics.

It will be understood that the lubricating compositions of the present invention may also contain, if desired, conventional lubricant additives such as ancillary antioxidants and anti-wear additives (preferably ashless), corrosion inhibitors, dispersants, particularly dispersants of the succinimide type, detergents, thickeners, pour-point depressants and viscosity index improvers. A particularly useful additive to be used in conjunction with the additives of the present invention is benzotriazole which has been found to reduce lacquer formation and improve the appearance of bearings in test engines lubricated with compositions of the present invention. The benzotriazole may, if desired. be incorporated prior to the sulphurisation reaction of the present invention or after sulphurisation but either before or after the removal of any oil-insoluble constituents.

The additives of the present invention may also be conveniently prepared as a concentrate consisting of a concentrated solution of a major amount of the additives and a minor amount of mineral oil, or as an additive package consisting of a concentrated solution in mineral oil of a major amount of a combination of the additives with one or more conventional additives. Such concentrates and packages are frequently very convenient forms in which to handle and transport additives and are diluted with further quantities of oil, and optionally blended with further additives. before use.

Hence in accordance with another aspect of the invention there is provided a solution comprising a major amount of one or more compounds having the formula (A) or one or more of the oil-soluble metal free. phosphorus-free products of the process of the invention and a minor amount of a lubricating oil. One or more conventional additives may be combined with the compounds of formula (A) or the oil soluble. metal-free, phosphorus-free products.

The present invention will now be illustrated with ref erence to the following examples:

EXAMPLE 1 A mixture of dicyclopentadiene (264g.m 20m) and triethylamine catalyst (132g) was added dropwise over a period of 1 hour to sulphur (128g, 4.0m) maintained at a temperature of about C. About half-way through this addition an exotherm to C. was n0 ticed and this was quickly controlled by air blast cooling and no further problems were encountered during the remainder of the addition. After completion of the addition the resulting reaction mixture was maintained at l40l45C. for a further 1 hour, whereafter about 0.2g hydroquinone was added to the resulting crude product.

The crude product was stripped under high vacuum (0.2mm. Hg) to a base temperature of C. (internal temperature 140C.) to yield 330g (84% by weight) of a distillate (predominantly unrcacted dicyclopentadiene). The residue was placed in a l litre separating funnel together with an amount of petroleum ether (B.Pt. 6268C.) sufficient to substantially fill the funnel resulting in a viscous, oily, petroleum etherinsoluble layer (yield 2l2.lg., 541% by weight) and a petroleum ether layer. The latter was separated and the petroleum ether stripped off to yield 149.2g. (38.2% by weight) of the final. oil-soluble product containing 32.5% sulphur.

EXAMPLE 2 Dicyclopentadiene (264g, 2.m) was added dropwise over a period of 40 minutes to sulphur (64g.2.0m) at l45C. The resulting reaction mixture was maintained at 145C. for a further hour and about 0.2g. hydroquinone added to the resulting crude product which was cooled and then stripped under high vacuum to a base temperature of 140C. to yield g (55.0% by weight) of unreacted dicyclopentadiene as distillate. The resi due was worked up in the same manner as in Example 1 to yield 66.3g. (20.2% by weight) of soluble material containing 31.0% sulphur and 18.9g (5.8% by weight) of oil insoluble product.

EXAMPLE 3 Dicyclopentadiene (264g, 2.0m), sulphur (64g, 2.0m) and triethylamine catalyst (13.2g.) were mixed and heated to 145C. for 2 hours. The resulting crude product was cooled slightly and about 0.2g hydroquinone added thereto. The crude product was then cooled and worked up in the same manner as in Example 2 to yield 116.7g (35.6% by weight) distillate, 532g (16.2% by weight) insoluble material and 155.0g (47.4% by weight) oil-soluble product containing 27.7% sulphur.

EXAMPLE 4 Dicyclopentadiene (238g, 1.8m) sulphur (64g, 2.0m), triethylamine catalyst 14.2g.) and, as solubilising agent, dibutyl maleate (45.6g 0.2m) were mixed and heated to l40150C. for 2 hours. Hydroquinone (about 0.2g) was added to the crude product which was then stripped to 120C. at 0.2mm Hg. to yield 83g. (23.9% by weight) distillate. The residue was worked up in the same manner as in Example 1 to yield about lg. insoluble material and 250.3g (72.0% by weight) oil-soluble product containing 24.7% sulphur.

EXAMPLE 5 TO 14 Further preparations were carried out in the manner of Example 4 and details thereof are given in the following Table 1.

EXAMPLE 15 A mixture of dicyclopentadiene 178g, 1.35m) dibutyl maleate (34.2g., 0.15m.) and triethylamine 10.6g.) was heated to 140C. and sulphur (72g, 2.25m) was added thereto over a period of 50 minutes during which the temperature was maintained at 140C. The temperature was maintained at 140C. for a further 70 minutes whereafter 0.2g. hydroquinone was added and the crude product stripped to 150C. 140C. internal temperature) at 0.1mm Hg. to yield 57g. (20.1% by weight) distillate. The residue was worked up in the same manner as in Example 1 to yield 32.6g.(11.5% by weight) insoluble material and 184.3g. (64.8% by weight) oil-soluble product containing 28.4% sulphur.

EXAMPLE 16 to 30 Further preparations were carried out in the manner of Example 15 and details thereof are given in the following Table 2.

EXAMPLE 31 Sulphur (144g. 4.5m.) was added incrementally over a period of 1 hour to a mixture of dicyclopentadiene (356g., 2.7m.) dibutyl maleate (68.4g., 0.3m.) triethylamine (21.2g.) and 2,5-dimercapto -1,3,4- thiadiazole (4.2g.) at a temperature of 160C. The reaction mixture was then maintained at 160C. for a further hour, whereafter it was stripped up to 110C. on a rotary evaporator under water pump vacuum (about 30mm Hg) to yield 2g. of distillate (excess dicyclopentadiene). The product was extracted with three times its volume of petroleum ether (boiling point 6268C.) yielding 75.1g. (13.7%) of insoluble material and petroleum ether stripped off the extract to yield 472.3g. (83%) of soluble material containing 25.0%S.

EXAMPLE 32 Example 31 was repeated except in that the reaction temperature was kept at 90C. and extraction with petroleum ether was not carried out to yield 184g. (50.4%) excess cyclopentadiene, no insoluble material and 386g. (68.0%) soluble product containing 35.5%8.

EXAMPLE 33 Example 32 was repeated, except in that the reaction temperature was kept at 120C., to yield 120g excess cyclopentadiene, no insoluble material and 455g. soluble product containing 31.9%S.

EXAMPLE 34 to 42 Further preparations were carried out in the manner of Example 33 and details thereof are given in the following Table 3.

EXAMPLE 43 Sulphur (172.8g., 5.4m.) was added incrementally over 1% hours, at a temperature of C., to a mixture of dicyclopentadiene (356g., 2.7m.), dibutyl maleate (68.4g., 0.3m.) diisopropylamine (5g.) and sodium sulphide powder (5g.). The reaction mixture was then stirred for a further 2 hours with the reaction temperature maintained in the range of 8590C. The resulting product was then filtered and stripped to 120C. under water pump vacuum to yield 83g. distillate (excess dicyclopentadiene). The stripped product (462g.) was not fully oil soluble and was therefore boiled with 1% litres petroleum ether to yield 350g. (59%) of soluble product containing 33.8%5.

EXAMPLE 44 Dicyclopentadiene (356g., 2.7m), dibutyl maleate (68.4g., 0.3m), diisopropylamine (4g) and 2,5-bis (toctyldithio) -l,3,4,-thiadiazole were dissolved in toluene (500ml) and sulphur (l72.8g., 5.4m) added thereto incrementally over 1 hour while maintaining a reaction temperature of 120C. The reaction mixture was then stirred for a further 1 hour at 120C. and vacuum stripped (removing toluene at C. and excess dicyclopentadiene at 120C.) to yield 461g. (76.7%) soluble product containing 34.1%8,

EXAMPLE 45 Example 44 was repeated using 500 ml petroleum ether (boiling point 80-100C.) in place of the toluene. The reaction temperature was maintained in the range of 100l10C. throughout due to the volatility of the solvent. In this way was obtained 469.9g. (78.2%) of soluble product containing 36.2%S.

EXAMPLE 46 Dicyclopentadiene (178g. 1.35m), dibutyl maleate (34.2g., 0.15m), di-isopropylamine (2g.) and 2,5-bis (octyldithio) -l,3,4-thiadiazole (2g) were dissolved in 200g. of high viscosity index 100 Solvent Neutral mineral oil. Sulphur (86.4g., 2.7m) was added incrementally over 1 hour at -l20C. and the reaction temperature maintained at C. for a further 1 hour. The product was vacuum stripped and filtered to yield 461g. (92.4%) of oil soluble product containing 19.0%S.

EXAMPLE 47 Dicyclopentadiene (178g. l.35m), dibutyl maleate (342g, 0.15m) di-isopropylamine (2g) were dissolved in 250ml toluene. Sulphur (129.6g. 4.05m) was added thereto over one-half hour at l ll20C. and the resulting mixture stirred for a further l V2 hours at lC. After vacuum stripping and filtration 300g (88%) of product containing 39.9%S was obtained. This gave a hazy solution in mineral oil indicating the presence of a very low level of insoluble material.

EXAMPLE 48 Example 44 was repeated except in that 172.8g. (5.4m) sulphur was used and a reaction temperature of 110C. was used. There was obtained 19] .4g. (49.9%) soluble product and 138.6g (36.1%) insoluble product.

EXAMPLE 49 S-Vinylnorbornene (84g. 0.7m), diisopropylamine (4.0g) and 2,5-bis (t-octyldithio) -l ,3,4-thiadiazole (0.8g) were mixed, heated to 130C. and sulphur (22.4g.. 0.7m) added thereto portionwise over 1 hour. The temperature was maintained at l30C. for a further 1 hour and the reaction mixture was stripped to 100C. at 0.1mm Hg. to remove 20.8g. (l9.6%) unreacted 5-vinylnorbornene. The product was extracted with 250ml petroleum ether (boiling point 6268C.) and filtered to remove a small quantity of insoluble material. The petroleum ether was stripped from the extract to yield 51g (48%) of soluble product.

In some of the foregoing examples (1 to 5. 9 l l and I8) 21 small quantity of hydroquinone was added to the crude product of the sulphurisation reaction since it was thought that the reaction proceeded by a free radical mechanism and that continuation of a free radical reaction during working up of the crude product could lead to some degradation. The hydroquinone was therefore used to suppress free radical reaction. However, subsequent experiences indicated that the use of hydroquinone did not materially improve the additive preparation.

Various products of the foregoing examples were tested to determine their suitability as lubricant addi- Extended Wl tests were carried out for typical test additives (in the same blends) by the same method except that oil samples removed from time to time were not replaced. Bearing Weight Losses were as follows:

In comparison a typical fully-formulated commercially available 1OW/50 oil containing a zinc dialkyl di thiophosphate as antioxidant, a succinimide-type dispersant, a metal sulphonate detergent, a polymethacrylate viscosity index improver and a combination of corrosion inhibitors gave bearing weight losses in this test of 15mg, 27mg and 68mg at 36, 72 and 108 hours respectively.

Load carrying properties were determined using the Timken OK load test according to the lP240/69T method (except in that results are quoted in lbs.) The test blends consisted of test additive dissolved in l50 Solvent Neutral mineral oil, the former being in amount to provide 0.3% by weight sulphur in the test blend and the results were as follows:

Timken OK Load (lbs) In comparison commercially available zinc dialkyl dithiophosphates usually give Timken OK loads of 35-40 lbs in this test.

Rotary Bomb Tests carried out by the IP 229/68T method on blends consisting of 2.0% by weight test additive dissolved in 500 Solvent Neutral mineral oil gave the following induction periods:

tives. Petter Wl Engine tests were carried out by the lnstitute of Petroleums method lP 176/69 using an ashless blend consisting of a commercially available suc- Test Additive Induction Period (minutes) cinimide-type dispersant. a secondary aromatic amine N bas l I antioxidant and a combination of corrosion inhibitors gg f g z 3 together with 1.0% by weight of the test additive all disdo. l] 178 solved in a 500 Solvent Neutral mineral oil. Bearing 33' iggus i l .S. S weight losses after a 36 hour test were measured and do, I9 216 25 gm. 13:5) were as follows: 3 I12 (25 p.s.i. loss) Test Additive Bearing Test Bearing Wcight Additive Wcight Loss (mg) Loss (mg) Product of Example l 9 Product of Example l5 l2 do. 3 17.4 do. l6 8 do. 4 9 do. 19 8 do. 5 d0. 2] 3 do. n a do. 22 17 do. K 7 do. 24 [9 do. l 5 do. 30 9 do. l3 5 do. 37 13 do. l-l IU Copper strip tests were carried out by the ASTM method except in that a temperature of 120C. was used. The blends tested consisted of sufficient test additive to provide a blend containing 0.15% dissolved in a 500 Solvent Neutral or a l50 Solvent Neutral mineral oil. ASTM ratings after 3 hours were as follows:

provided with interengaging surfaces lubricated with the test blend and are driven at speeds in a ratio of 14.6:1. After a short running period the load on the interengaging surface is incrementally increased until 5 scuffing occurs. With a blend consisting of an S.A.E. 90

base oil, 4.5% by weight of an additive in accordance From the foregoing test results it can be seen that the additives of the present invention impart antioxidant properties (Rotary Bomb Test) and yet have a low level of corrosiveness (Copper Strip Test) despite the high sulphur content. Furthermore in the standard tests the additives demonstrate load carrying abilities (Timken OK load Test) and test engine performance (Peter WI Tests) in fully formulated blends similar to those exhibited by the zinc dialkyl dithiophosphates normally used in premium grade crankcase lubricants.

The suitability of the additives of the present invention for use in gear oil formulations was determined by use of the S.A.E. tests in which two parallel shafts are 30 with the present invention (containing 30.3%8) and 0.5% by weight di-isopropyl phosphite scuffing resulted at 245 lb and 230 lb (duplicate tests) at a drive shaft weight di-isopropyl phosphite resulting in seuffing at 265 lb and 310 lb. Thus the blend containing the additive according to the present invention produced similar test results even though the sulphur content was substantially less than in the comparison blend.

TABLE l Examples 5 to 7 (Columns l to 5) inclusive Example Dicyclo Soluhilising Reaction No. pcnladienc Agent Sulphur Catalyst Conditions Tetramethyl 5 264g None 64g thiuram di- 2 hrs. at

2.0m 2.0m sulphide l4llC.

lllg

'l'riethyl- 6 238g Dihutyl 64g amine 2 hrs. at 1.3m Maleatc lllm 14 2g l4l)(.* 456g, 72m DMTZ 2.8g

7 264g None (4g Tricthyl 2 hrs. at

2.0m lllm amine l4(lC.

lllg Examples 5 to 7 (Columns 6 to R) lnelusive Example Stripping Yield Qr'S in No. Conditions soluble (removing Distillate insoluble Soluble product unreacted Weight '72 Weight Q Weight '71 dicyclolg) (g) lg) pcntndicnc) l lUC at lIS 38.2 b 231) lI-l 37.9 32 5 5 0.1 mmHg l3(lC. at I13 35.4 (l (I ll} bl 3 8.6 h (HmmHg NUT. at llh 35.4 52. m1 l4l 7 43 28.5 7 U. lmmHg l tamplcs X to 12 (Columns l to 5) inclushc Example Dodecenyl 'l'ricthyl- 8 238g Succmie (id-g amine 2 hrs. at Him Anh dride lllm l4.3g C.

47 fig, ll lttm 9 198g clodndeca- (Hg Triethyl- 2 hrs. at

1.5m LEM-menu lllrn amine 140C.

82g. (him 140g TABLE 1 --Continued 10 238g Octyl 64g Tricthyl- 2 hrs. at

1.11m Mcthacrylatc 2.0m amine 140C.

39.6g. 0.2m 13.9g

1 1 238g Cyclododecu- 64g Triethyl- 2 hrs. at

1.8m 1.5.9-triene 2.0m amine 140C 328g. 0.2m 13.5g

12 238g Alloocimcnc 64g Tricthyl- 2 hrs. at

1.8111 27.2g.0.2m 2.0 amine 140C.

Examples 8 to 12 (Columns 6 to 8) inclusive Example 140T. at 106 30.3 236.5 67.6 26.5

No. 0.1mmHg 9 120C. at 113.5 32.) 20.0 5.8 207.1 60.2 26.8

0.1mmHg l0 145C. at 124 36.3 25.5 7.5 172.3 50.4 27.2

0.1mmHg ll 1 10C. at 108.4 32.2 37.11 11.0 182.3 54.5 26.9

0.1mmHg l2 120C. at 95.1 29.0 2.3 0.? 229g 69.8 27.3

0.1mmHg Examples 13 and 14 (Columns 1 t0 5) inclusive Example 13 238g Cyclododeca 64g Tricthyl- 2 hrs. at

1.8m l ,5 .9-tricne 2.0m amine 140C.

l4 23kg Cyclododccu 64g Triethyl- 2 hrs. at

1.8m 1.5 .9-trienc 2.0m amine 140C.

32.4g.0.2m 13.5g

0.1% of t-butyl hydroperoxide Examples 13 and 14 (columns 6 to 8) Inclusive Example C. at 146 43.7 68.1 211.4 98.5 29.5 31.3

N0. 13 0.1mmHg 14 105C. at 131 39.2 40g 140.7 42.1 29,6

0.1mmHg On initial heating a sharp cxotherm was noticed at an internal temperature 01' 100-1 10C. The exmherm raised temperature tn about 160C. The temperature then settled back In C. and thereafter the reaction pmccedcd smumhly for 2 huurs TABLE 2 Examples 16 to 18 (Columns 1 to 5) inclusive Example Dicyelo- Solubilising Sulphur Catalyst Reaction No. pentadicne Agent Conditions 16 158.11g Allooeimenc 96g Tricthy1- Addition of S 1.2m 408g. 0.3m 3.0m amine over 1% hrs at 100g 140C further 1% hr. at 140C 17 198g None 72g Triethyl- Addition of S 1.5m 2.25m amine over 1 hr. at

9.9g 140C. further 1 hr. at 140C.

18 178g Allooeimene 72g Tricthyl- Addition of S 1.35m 20.4g.0.l5m 2.25m amine over 36 hr. at

9.9g 140C. further 1% hrs at140C.

Table 2 Continued Examples If: to 18 (Columns 6 to 8) inclusive Example Stripping Yield 705 in No. Conditions soluble product (removing Distillate insoluble Soluble unreaeted dicyclo- Weight Weight Weight pentudiene) (g) (g) (g) 16 145T. at 5 1.6 133.4 45.3 138 46.8 28.4

0.1mmHg 17 140C. at 43 15.9 86.0 31.9 125.5 46.5 28.0

0.1 mmHg 18 130C. at 32 [1.8 47.5 17.6 172.8 63.8 26.8

0.1mmHg Examples 19 to 22 (Columns 1 to 51 inclusive Example 19 178g tDodecyl 72g Tn'ethyl- Addition of S 1.35m Mcrcaptun 225m amine over mins at 325g, 0.15m g 140C. further 50 mins at 140C.

20 178g Oleic acid 72g Triethyl- Addition of S 1.35m 423g. 0.15m 2.25m amine over 1 hr. at

1 g 140C further 1 hr. at 140C.

21 178g Mereapto- 72g Triethyl- Addition of S 1.35 benzothiuzolc 2.25m amine over '70 mins at 25.0g, 0.15m 10.1g 140C further 50 mins at 140- 22 178g Ethomcen* 72g Triethyl- Addition of S 1.35m T 15 2.25m amine over 70 mins at 724g [2.5g 140C. further 50 mins at 140- 150C.

Examples 19 to 22 (Columns 6 to 8| inclusive Example No. 1) 150C. u! 21 7.4 25. 8.8 213.9 75.6 26.7

0.2mmHg 20 140C. at 32 10.9 40.4 13.8 198 67.8 22.2

0. lmml-lg 2| 143C. at 35 12.) 34.4 12.5 198.3 721 32 2 0.1mmHg 22 150C. at 23 7.2 21.1 6.6 256.3 79.6 2' (1 0. lmmHg Examples 23 to 35 (Columns 1 to 51 inclusive Example 23 216g Dibutyl 72g Triethyl- Addition of S 1.35m Maleatc 2.25m amine over 1 hr at 342g. 0.15m g C. further 1 hr at 140C.

24 I78 t-dodeeyl 72g TriethyL Addition of S 1.35m mercuptun 2.25m amine 10.5 over 1 hr at 30.3g,0.15m 2,5-Dimer 140C further cuptol 1 hr at 140C. 3.4,thiu diazole 2.4g

25 356g Dibutyl l44g Triethyl- Addition of S 2 7m mulcate 4.5m amine over [V4 hr. at 140C 6K.4g.0.3m 212g further hr at 140C. 2,5-dimer capto- 1,3.4 thiadiuzolc 4.2g

TABLE 2 Continued Examples 23 to 25 ((olumm h tu K] inclusive Example 140C at 45 1-1- 0 258.7 80.4 24,6

N0. 0.1mmHg 24 140C. at 380 13.5 11.2 4.0 220 78 I 29.9

0.1mmHg 25 140C. at I063 187 0 0 431 76.0 30.3

0.1mmHg Examples 26 to (Columns 1 to 5) inclusive Example 26 178g Dicyelop 72g Triethyl- Addition of S 1.35m entudicne 2.25m amine over 1% hr. at 140C.

hydrate. 10.0g further hr at 22.5 ,0.15m lC.

27 178g lsodccanol 72qg Tricthyl- Addition of 5 1.35m 23.7g,0.l5m 2.2. m amine over 1% hr. at 140C 101g further 5 1 hr at 140C.

28 187.97; Dimer acid 72g Triethyl- Addition of S 1.42Sm 42.8g;0.075n1 2 25m amine over 1% hr at 140C.

I 1.6g further V4 hr at 140C.

29* 356g Dodcccnyl 144g Triethyl- Addition of S 2.7m suecinic 4.5m amine over 1% hr at 140C.

an hydride 228g further 34 hr 111 79.x ,0,3m 140C.

30* 178g Dihutyl Tricthyl Addition of S 1.35m Malcute 72g amine over 1% hrs at 140C.

34.2g((l.15m) 2.25m 106g 9 hr at 140C.

Examples 26 to 30 (Cnlumns 6 l0 8) inclusive Example 150C. at 42.0 15.4 83,5 30.7 [37 50.4 27.7

N0. 26 llllmmHg 27 145C. at 18.2 92.5 33.6 129.4 47.3 27.4

0.1mmHg 211 145C. at 28 9.2 67 22.1 195 58.5 "1.8

0.1mmHg 29 140C. at 41 7.1 53.2 9.2 483 83.4 24.7

0,1mmHg 310 140C at 32 11.3 24.1 8,5 221.6 78 26.1

0. lmmHg EXAMPLES 16 in 30 'Elhnmeen T 15 is a Commercially mail-able ctlhuxylatcd lilllfi amine of average molecular weight 482 and Containing an average of S ethylene oxide residues per mulccule. "Methylc clupcnlzidicnc dimer used in place of dicyclnpentadienc.

"'Ben/oirin/ule (4.4g and 2.2; in Examples 29 and 30 respectively) present during sulphurisation.

TABLE 3 Examples 34 to 35 (Columns 1 to 5) inclusive Example Dicyclu- Solubilising Reaction Nu. pentadicne Agent Sulphur Catalyst Conditions 34 356g. Dibutyl 172l8g Cyclohcxyl- Addition of S 2.7m Malcatc 5.4m amine over 1 hr at 12.5g 7.5g C. further 2,5-Dimerc- 1 hr at 120C. limo-1.3.4- thiudiazole 3.7g

35 356g... Dihutyl 172.1'4g Primcne 81R Addition of S 2.7m Malcatc 5.4m 15g over 1 hr at g 2.5-Dimcrc 120T. further llpIU-l,3,4- 1 hr at 120C. thiadiazule Table 3 Continued Ewmple 34 and 35 Columns (1 to 1 mclusiw Stripping YIELD 48 in Condition Soluhle Product Example (removing Distillate Insoluble Soluble No unreaeted dicyekr Weigh! f! Weight 1' Weight W penladicnel lg) (gl (g1 34 IlUC at 94 26 4 A l],l 423 797:

about 30mm [NFCv a! 88 24.7 ().l 467 83 4 37.|

Examples 36 to 38 (Columns l to 5) inclusive Example 30 Sing. None 1718;; Di-n-butyl- Addition of S 17m 5.4m amine mar 1 hr a! (wig 120C further 2.5-Dimcrc- 1 hr at l20C ap10-l.3,4' thiadiazole 3.7g

3? 56g. Dihuiyl l'lllig lS-Dimerc Addition of S 2.7m Maleate 5 4m aptul,3 4 met 1 hr at 115g thiadiiizole I'JUC. further 17g l hr 211 120C Di-isupropylamine 7.6g

38 356g Dihutyl l72l'ig Triethyl Addition of S 2 7m Mulealc 54m amine over 1 hr at l2.5g Silg 120C further LS-Dimcrc- 1 hr .1! 120C uptol .3 .4- thladiazole 17g Examples 36 to 33 (Columns 6 to 81 inclusive Example l 10C. at V9.7 ().l 424 2 78 N0 about 36 lllmm 37 l|UC at 9| 256 U.1 429.3 795 384 about 30mm 33 ll(|C, a! 82 23 (ll 45! 83.3 36.]

about 30mm Examples 39 to 4| {Columns to 5) inelushc Example 39* 356g, Dihul l 1718 Di-isoprupfl Addition of S 17m Maleate 54m amine over I hr at hK-lgllflm g |20C. +further 25bis(tl hr at l2UC octyl-dilhio) -l ,3.-lthiadiazole 40g 4U 356g. Dihutyl l7l8g Di-isopropyl Addition of S 2.7m Maleatc 54m amine over 1 hr at fihlgllflm 4.0g lZOC further ls-bislt- 1 hr at IZUC oetyl-dithio) -l.3 4- thiadiazolc -llllg 4l 35fig None lTlKg Di-isuprop 'l Addizinn of S I "m 5.4m amine met I hr at 40g I2UC +furlher 2.5-hisitl hr an C oclyl-dithio) l 3,4-

Lhiadiazole 411g TABLE 3 (on1inucd livnrnplcs .W to 4| lfolumns h to R| inclusiw liirlmplc ll()(' at 9-3 2h 4 0.1 4301 78.9 33.2

No. about 39 30mm 40 l 10C. at 85 23.) I l) 1 484.5 80.3 34.4

about 30mm ll ll()(. at ll.l 4tl5.l 75.4

about 30mm limmplc 42 [Columns I to 5 inclusiw Example 4-2 356g. Dibutyl 172.14g Di-isupropyl Addition of S 2.7m Mnlcntc 5.4m amine ovcr l hr at h8.4g.(l.3m 4.0g l20C. furthcr 2.5-bis[l 1% hr at l20C.+ uctyldithio) addition of 4.0 34- Bcnzotriazolc thiudiuzolc further it hr at 4.0g l20C.

Example 42 (Columns (1 to 8) inclusive Example [20C at US 32.3 ll.l 426 70.4 34.5

No. 42 about 30mm Hg.

"LS-[)imcrcapln -l..1.4-thi:ulia/olc 13 7g] formed in situ by heating carbon disulphide (Big) and hydra/inc hydrate 1 115g) in the dic \clopcntntliene for hour at 50C. Thereafter the di-isnpmpylamlnc was added and sulphurisutinn carried out. "licn/nlrln/nlc 7g in Example 35 and 4.0g in each of Examples 39 and JI present during sulphunsution wherein:

a. each of R, R and R when taken singly is selected from the group consisting of a hydrogen atom. an alkyl group containing from 1 to about 15 carbon atoms, an aryl group containing from 6 to about 15 carbon atoms and a cycloalkyl group containing from 4 to about carbon atoms;

b. each of R and R when taken singly is selected from the group consisting of a hydrogen atom, an alkyl group containing from 1 to about carbon atoms, an aryl group containing from 6 to about 15 carbon atoms, a cycloalkyl group containing from 4 to about 10 carbon atoms and an alkenyl group containing from 2 to about 10 carbon atoms;

. R and R when taken together from the group -CHY.CY CY in which Y is a hydrogen atom or a methyl group;

d. R when taken together with R forms an alkylidene group containing from 1 to about 6 carbon atoms; and

e. R is selected from the group consisting ofa hydrogen atom and an alkyl group containing from I to about 15 carbon atoms; and (2) an oil-soluble sulphurised norbornenyl product resulting from sulphurising a compound having the general formula:

wherein R, R, R R, R and R are as hereinbefore defined at a temperature of up to lC.. said sulphurisation being carried out in the absence of a solvent or in the presence of a non-polar solvent.

2. A lubricating composition according to claim 1 wherein the additive is a compound having the Formula (A) as hereinbefore defined.

3. A lubricating composition according to claim 2 which comprises from 0.1 to l0 by weight of the additive.

4. A lubricating composition according to claim 1 which incorporates a minor amount of benzotriazole therein.

5. A lubricating composition according to claim 4 wherein the benzotriazole is present in an amount of from 0.0025 to 0.1% by weight.

6. A lubricating composition according to claim 1 wherein the additive is an oil soluble sulphurized norbornenyl product resulting from sulphurizing a compound having the formula (B).

7. A lubricating composition according to claim 6 which comprises from 0.1 to 10% by weight of the additive.

8. A lubricating composition according to claim 6 wherein the compound having the formula (B) is dicyclopentadiene or an alkyl substituted dicyclopentadiene and said sulphurization has been carried out at a temperature of from to C.

9. A lubricating composition according to claim 8 which comprises from 0.25 to 5 percent by weight of the additive.

10. A lubricating composition according to claim 8 wherein said sulphurization has been carried out in the presence of an amine sulphurization catalyst.

11. A lubricating composition according to claim 6 wherein said sulphurized norbornyl product is that resulting from sulphurizing a compound having the formula (B) with from about I to 2 moles of sulphur per mole of compound.

12. A lubricating composition according to claim 10 wherein said sulphurization has been carried out in the presence of a solubilizing agent selected from the group consisting of alloocimene, dibutyl maleate, dodecenyl succinic acid, t-dodecyl mercaptan, ethoxylated tallow amine having an average molecular weight of 482 and containing an average of 5 ethylene oxideresidues per molecule, oleic acid, l,5,9-cyclododecatriene and mercaptobenzothiazole.

13. A concentrate for addition to a lubricating composition, said concentrate comprising a minor amount of a mineral oil and a major amount of a sulphurcontaining additive selected from the group consisting of (l) sulphurised norbornenyl compound having the general formula:

wherein:

a. each of R, R and R when taken singly is selected from the group consisting of a hydrogen atom, an

alkyl group containing from 1 to about 15 carbon atoms, an aryl group containing from 6 to about 15 carbon atoms and a cycloalkyl group containing from 4 to about 10 carbon atoms;

b. each of R and R when taken singly is selected from the group consisting of a hydrogen atom, an alkyl group containing from 1 to about [5 carbon atoms, an aryl group containing from 6 to about 15 carbon atoms, a cycloalkyl group containing from 4 to about 10 carbon atoms and an alkenyl group containing from 2 to about 10 carbon atoms;

0. R and R when taken together from the group CHY.CY CY in which Y is a hydrogen atom or a methyl group;

d. R when taken together with R forms an alkylidene group containing from 1 to about 6 carbon atoms; and

e. R is selected from the group consisting of a hydrogen atom and an alkyl group containing from 1 to about 15 carbon atoms; and (2) an oil-soluble sulphurised norbornenyl product resulting from sulphurising a compound having the general formula:

wherein R, R R R R and R are as hereinbefore defined at a temperature of up to C, said sulphurisation being carried out in the absence of a solvent or in the presence of a non-polar solvent. 

1. A LUBRICATING COMPOSITION CONTAINING A MAJOR AMOUNT OF LUBRICATING OIL AND A MINOR ANTI-OXIDANT OR LOAD-CARRYING AMOUNT OF A SULPHUR-CONTAINING ADDITIVE SELECTED FROM THE GROUP CONSISTING OF (1) SULPHURISED NORBORNEYL COMPOUND HAVING THE GENERAL FORMULA:
 2. A lubricating composition according to claim 1 wherein the additive is a compound having the Formula (A) as hereinbefore defined.
 3. A lubricating composition according to claim 2 which comprises from 0.1 to 10 by weight of the additive.
 4. A LUBRICATING COMPOSITION ACCORDING TO CLAIM 1 WHICH INCORPORATES A MINOR AMOUNT OF BENZOTRIAZOLE THEREIN.
 5. A lubricating composition according to claim 4 wherein the benzotriazole is present in an amount of from 0.0025 to 0.1% by weight.
 6. A lubricating composition according to claim 1 wherein the additive is an oil soluble sulphurized norbornenyl product resulting from sulphurizing a compound having the formula (B).
 7. A lubricating composition according to claim 6 which comprises from 0.1 to 10% by weight of the additive.
 8. A lubricating composition according to claim 6 wherein the compound having the formula (B) is dicyclopentadiene or an alkyl substituted dicyclopentadiene and said sulphurization has been carried out at a temperature of from 90* to 180*C.
 9. A lubricating composition according to claim 8 which comprises from 0.25 to 5 percent by weight of the additive.
 10. A lubricating composition according to claim 8 wherein said sulphurization has been carried out in the presence of an amine sulphurization catalyst.
 11. A lubricating composition according to claim 6 wherein said sulphurized norbornyl product is that resulting from sulphurizing a compound having the formula (B) with from about 1 to 2 moles of sulphur per mole of compound.
 12. A lubricating composition according to claim 10 wherein said sulphurization has been carried out in the presence of a solubilizing agent selected from the group consisting of alloocimene, dibutyl maleate, dodecenyl succinic acid, t-dodecyl mercaptan, ethoxylated tallow amine having an average molecular weight of 482 and containing an average of 5 ethylene oxideresidues per molecule, oleic acid, 1,5,9-cyclododecatriene and mercaptobenzothiazole.
 13. A concentrate for addition to a lubricating composition, said concentrate comprising a minor amount of a mineral oil and a major amount of a sulphur-containing additive selected from the group consisting of (1) sulphurised norbornenyl compound having the general formula: 